1. Field of the Invention
The present invention relates to a fuel-gas lighterxe2x80x94more particularly a utility lighter with a safeguard.
2. Description of Prior Art
Utility lighters are used for inflaming barbeque grills, fireplaces, candles, and other firing fields in daily life. Such a lighter, as shown in FIG. 5 and FIG. 6, is comprised of a gas container 4, a shell 2, and a long rod-like tube 3 for inflaming objects in hard-to-reach places. The gas container 4 contains highly compressed inflammable gas. Fuel lever 6 controls the opening and closing of gas container 4""s outlet. The friction force generated by pressing down trigger 8 activates piezoelectric unit 7 that is located on the inside of shell 2, and releases the fuel to inflame the lighter.
When the user presses said trigger 8 with his finger, it contacts said lever 6, lifting the valve to emit the gas from container 4 to the end of tube 3. The pressing motion also activates the piezoelectric unit, generating a spark at the outside tip of barrel portion 3, which in turn creates the flame.
Although this utility lighter conveniently inflames objects in hard-to-reach places by keeping the user""s hand and face away from the flame, its gun-like shape promotes unsafe behavior in children who may mistake the lighter for a toy. Such behaviors may lead to fires and burn injuries. To prevent the utility lighter from being activated inadvertently by children, many lighters in the market are now equipped with a trigger-locking device.
A conventional utility lighter, such as that shown in FIG. 7, has a sliding switch 20 mounted on the handle""s side. When the switch 20 is set to the xe2x80x9cOnxe2x80x9d position, the switch""s stopper withdraws from trigger 8, allowing it to slide freely. Conversely, when the switch 20 is set to the xe2x80x9cOffxe2x80x9d position, the switch""s stopper blocks trigger 8, preventing the steps necessary to create a flame. Unfortunately, the users of lighters with safety functions designed in this way often forget to set switch to the xe2x80x9cOffxe2x80x9d position after using, defeating the purpose of the mechanism.
It is, therefore, a main object of the present invention to provide a lighter with an automatic safeguard so that inadvertent activation by children can be prevented.
The utility lighter of the present invention has a safeguard, which is comprised of a shell with a barrel portion, a gas container, a piezoelectric unit, and a safety device comprised of a trigger and a safety button. The piezoelectric unit is placed between a holding plate of the trigger and a blocking plate of the safety button that is backed by a compression spring. A locating plate is built on the shell to coordinate with the position of the safety button.
The piezoelectric unit has a sliding portion equipped with a hammer backed by a compression spring that is loaded inside the unit. The sliding portion travels the pre-set striking distance needed to hit the piezocrystal placed inside the unit for producing a spark.
The distance between the trigger""s original position and the trigger""s pressed position, called the trigger""s travel distance, should be equal or greater than the striking distance of the sliding portion of the piezoelectric unit in order to generate a spark. Conversely, the travel distance should be lesser than the sum of the striking distance of the piezoelectric unit and the travel distance of the safety button in order to create the safeguard.
The said safety button has a blocking plate that extends inside the shell blocking the bottom end of the piezoelectric unit. A portion of the safety button extends out of the shell to form a button to be pressed by the user""s thumb.
A locating plate is built inside the shell, opposite the backside of the safety button""s blocking plate. A compression spring connects the two plates and holds the blocking plate upright. The elasticity of this compression spring should be less than that of the compression spring built on the inside of the piezoelectric unit.
The trigger has a holding plate at one end that extends inside the shell, holding the end of the sliding portion of the piezoelectric unit at the back-end, opposite the blocking plate of the safety button. The other end of the trigger extends to engage with the fuel lever.
A safety button is added to the common utility lighter, and a piezoelectric unit is placed between the trigger and the safety button, so it can move following the trigger action. The movement of the piezoelectric unit can be blocked or allowed, depending on whether or not the safety button is retained at its original position. When the user presses the safety button at the external of the lighter and sustains it at original position, the piezoelectric unit is blocked, and a spark is generated. If the safety button is free, the piezoelectric unit is allowed to slide backward so the trigger is unable to strike it, preventing the generation of the spark. Children will find it difficult to figure that the safety button need be pressed and sustained to create a flame. Therefore, such a lighter would greatly reduce fire damage or injury caused by a child""s inadvertent activation. At the same time, an adult can use it without significant inconvenience. The structure of such a utility lighter would be simple enough to be easily manufactured.